1. Technical Field
The present disclosure relates to a printer for an automatic packing machine and, more particularly, to a printer for an automatic packing machine and a method of controlling the same which employs a ribbon cartridge for providing a ribbon tape to facilitate replacement of the ribbon tape and allows a thermal print head to be lifted or lowered to further facilitate replacement of the ribbon tape, and which can adjust an unwinding speed of the ribbon tape through detection of a remaining amount of the ribbon tape during printing.
2. Description of the Related Art
Conventionally, an automatic packing machine receives medicine from a plurality of cassettes, which receive medicines such as tablets or capsules and consecutively packs the medicine into doses.
FIG. 1 is a schematic front view of a conventional automatic packing machine. Referring to FIG. 1, the automatic packing machine includes a body 100, a plurality of cassettes 110, which are arranged at an upper portion of the body 100 and receive medicines including tablets or capsules having various sizes and shapes, a hopper 130 disposed at a lower portion of the body 100 and collecting medicines discharged from the cassettes 110, a printer 140 for printing various medicine data on the surface of a wrapping paper for packing the medicines, and a packing machine 150 that packs the medicines using the wrapping paper when the medicines are collected in the hopper 130.
In such a conventional automatic packing machine, when medicines discharged from the cassettes 110 are collected in the hopper 130 and provided to a wrapping paper folded in half, the wrapping paper is passed through cylindrical bonding rollers provided with a heater to pack the medicines in a sealed state through thermal bonding of the wrapping paper. The packing machine is provided with a printer 140 to print data of the medicines on the wrapping paper.
Korean Patent No. 0521720 discloses one example of a conventional printer for an automatic packing machine. In this document, the printer prints medicine data on an outer surface of the wrapping paper using a thermal print head and a ribbon tape. At the moment of printing operation, the wrapping paper and the ribbon tape pass through the contact roller and the thermal print head while being stacked and compressed.
Here, since the ribbon tape is wound in a reel shape, the unwinding amount of the ribbon tape is changed according to the remaining amount of ribbon tape on a reel of the ribbon tape. That is, in an initial stage with 100% of the ribbon tape remaining on the reel, the amount of ribbon tape to be unwound by a single rotation of the reel is different from that of the ribbon tape to be unwound by a single rotation of the reel in a final stage with substantially 0% of the ribbon tape remaining on the reel.
However, since the conventional printer rotates the reel of the ribbon tape at a constant speed without considering the wound state of the ribbon tape around the reel, tension applied to the ribbon tape is not kept constant, causing deterioration of printing quality.
Further, when the ribbon tape is wound in the form of two reels, it is necessary to separate and mount these two reels at the same time upon replacement of the ribbon tape, making replacement inconvenient and providing a possibility of damage of the ribbon tape during replacement.
Furthermore, since the ribbon tape is interposed between the contact roller and the thermal print head, which are brought into close contact with each other to be compressed against each other by constant pressure, it is necessary for the printer to allow the thermal print head to be easily separated from the contact roller upon replacement of the ribbon tape.